A common problem with differences-in-differences (DD) estimates is the failure of the parallel-trend assumption. To cope with this, most authors include polynomial (linear, quadratic…) trends among the regressors, and estimate the treatment effect as a once-in-a-time trend shift. In practice...

A common problem with differences-in-differences (DD) estimates is the failure of the parallel-trend assumption. To cope with this, most authors include polynomial (linear, quadratic…) trends among the regressors, and estimate the treatment effect as a once-in-a-time trend shift. In practice...

According to the literature on work-sharing, productivity gains on capital equipment may increase employment while diminishing weekly working hours. In this article, we evaluate the impact of the French 35-hour working week on capital operating time. We merge the French survey on Capital...